Opal occurs as nodules in volcanic rocks at a new gem opal locality in the Menz Gishe district of Shewa Province, Ethiopia.

Demantoid, green andradite garnet, was discovered in the Central Ural Mountains of Russia in the mid-19th century.

This article explores the mining developments and new diamond occurrences in Africa that led to many of the key concepts in modern geology.

A new type of Russian hydrothermal synthetic emerald is produced by seeded growth in steel autoclaves without noble-metal inserts; the seed slices have been cut parallel to a face of the second-order hexagonal dipyramid s (1121).

For more than 100 years, Africa has produced large commercial quantities of diamonds and important individual stones.

One of the most interesting of the commercially available Czochralski pulled synthetic corundums is pink “Ti-sapphire.”

The history of Baja California has been closely tied to the exploitation of pearls since the 16th century.

This article illustrates the various features in filled diamonds and explores the best techniques for examining them.

The emeralds of the Ural Mountains, in what is now called the Russian Federation, have been known for more than 160 years.

Yogo Gulch, discovered more than 100 years ago, is one of four major sapphire-producing areas in Montana, United States.

Many deposits of gem corundum are associated with alkali basalt.

Primary occurrences of ruby, pink sapphire, sapphires of other colors, and spinel have been found in marbles in the Ural Mountains.

Inclusions of native copper and tenorite (CuO) were found in grayish green elbaite from São José da Batalha, Paraíba, Brazil.

Northern Vietnam began producing significant quantities of rubies and fancy sapphires in the late 1980s.

Although the reign of King Edward VII of Great Britain was relatively short (1902-1910), the age that bears his name produced distinctive jewelry and ushered in several new designs and manufacturing techniques. During this period, women from the uppermost echelons of society wore a profusion of extravagant jewelry as a way of demonstrating their wealth and rank. The almost exclusive use of platinum, the greater use of pearls, and the steady supply of South African diamonds created a combination that will forever characterize Edwardian jewels. The Edwardian age, truly the last era of the ruling classes, ended dramatically with the onset of World War I.

Renewed interest in large-scale commercial mining of Montana sapphires motivated a detailed study of the heat treatment of sapphire from the Rock Creek deposit.